I am the spiritually conscientious one, answered he who was asked, and in matters of the spirit it is difficult for any one to take it more rigorously, more restrictedly, and more severely than I, except him from whom I learnt it, Zarathustra himself.

Better know nothing than half-know many things! Better be a fool on one’s own account than a sage on other people’s approbation! I — go to the basis:

What matter if it be great or small? If it be called swamp or sky? A handbreadth of basis is enough for me, if it be actually basis and ground —

A handbreadth of basis: thereon can one stand. In the true knowing-knowledge there is nothing great and nothing small.

Then thou art perhaps an expert on the leech? asked Zarathustra. And thou investigatest the leech to its ultimate basis, thou conscientious one?

O Zarathustra, answered the trodden one, that would be something immense; how could I presume to do so!

That, however, of which I am master and knower, is the brain of the leech: that is my world!

And it is also a world! Forgive it, however, that my pride here findeth expression, for here I have not mine equal. Therefore said I: ‘here am I at home.’

How long have I investigated this one thing, the brain of the leech, so that here the slippery truth might no longer slip from me! Here is my domain!

For the sake of this did I cast everything else aside; for the sake of this did everything else become indifferent to me; and close beside my knowledge lieth my black ignorance.

My spiritual conscience requireth from me that it should be so — that I should know one thing, and not know all else; they are a loathing unto me, all the semi-spiritual, all the hazy, hovering and visionary.

Where mine honesty ceaseth, there am I blind, and want also to be blind. Where I want to know, however, there want I also to be honest — namely, severe, rigorous, restricted, cruel and inexorable.

Because thou once saidest, O Zarathustra: ‘Spirit is life which itself cutteth into life’ — that led and allured me to thy doctrine. And verily, with mine own blood have I increased mine own knowledge!

As the evidence indicateth, broke in Zarathustra; for still was the blood flowing down on the naked arm of the conscientious one. For there had ten leeches bitten into it.

O thou strange fellow, how much doth this very evidence teach me — namely, thou thyself! And not all, perhaps, might I pour into thy rigorous ear!

Well then! We part here! But I would fain find thee again. Up thither is the way to my cave; tonight shalt thou there be my welcome guest!

Fain would I also make amends to thy body for Zarathustra treading upon thee with his feet: I think about that. Just now, however, a cry of distress calleth me hastily away from thee.

Thus spake Zarathustra.